Temporal and compartment-specific signals coordinate mitotic exit with spindle position

Nat Commun. 2017 Jan 24;8:14129. doi: 10.1038/ncomms14129.

Abstract

The spatiotemporal control of mitotic exit is crucial for faithful chromosome segregation during mitosis. In budding yeast, the mitotic exit network (MEN) drives cells out of mitosis, whereas the spindle position checkpoint (SPOC) blocks MEN activity when the anaphase spindle is mispositioned. How the SPOC operates at a molecular level remains unclear. Here, we report novel insights into how mitotic signalling pathways orchestrate chromosome segregation in time and space. We establish that the key function of the central SPOC kinase, Kin4, is to counterbalance MEN activation by the cdc fourteen early anaphase release (FEAR) network in the mother cell compartment. Remarkably, Kin4 becomes dispensable for SPOC function in the absence of FEAR. Cells lacking both FEAR and Kin4 show that FEAR contributes to mitotic exit through regulation of the SPOC component Bfa1 and the MEN kinase Cdc15. Furthermore, we uncover controls that specifically promote mitotic exit in the daughter cell compartment.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosome Segregation / physiology
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism
  • Genes, Fungal / physiology*
  • Guanine Nucleotide Exchange Factors / genetics
  • Guanine Nucleotide Exchange Factors / metabolism
  • MAP Kinase Kinase Kinases / genetics
  • MAP Kinase Kinase Kinases / metabolism
  • Mitosis / physiology*
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism
  • Saccharomyces cerevisiae / physiology
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism
  • Signal Transduction / physiology*
  • Spindle Apparatus / physiology*

Substances

  • BFA1 protein, S cerevisiae
  • Cytoskeletal Proteins
  • Guanine Nucleotide Exchange Factors
  • LTE1 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • KIN4 kinase, S cerevisiae
  • Protein-Serine-Threonine Kinases
  • MAP Kinase Kinase Kinases
  • STE20 protein, S cerevisiae